if (document.images)
{
  preload_image_object = new Image();

  image_url = new Array();
  image_url[0] = "images/navBar/en/btnOnasHover.png";
  image_url[1] = "images/navBar/en/btnOfertaHover.png";
  image_url[2] = "images/navBar/en/btnUslugiHover.png";
  image_url[3] = "images/navBar/en/btnWspolpracaHover.png";
  image_url[4] = "images/navBar/en/btnKontaktHover.png";
  image_url[5] = "images/navBar/pl/btnOnasHover.png";
  image_url[6] = "images/navBar/pl/btnOfertaHover.png";
  image_url[7] = "images/navBar/pl/btnUslugiHover.png";
  image_url[8] = "images/navBar/pl/btnWspolpracaHover.png";
  image_url[9] = "images/navBar/pl/btnKontaktHover.png";

	  for (i = 0; i <= 10; i++) {
	   		preload_image_object.src = image_url[i];
	  }
}